The class of polymers of carbon monoxide and olefin(s) has been known for some time. Brubaker, U.S. Pat. No. 2,495,286, produced such polymers of relatively low carbon monoxide content in the presence of free radical initiators, e.g., peroxy compounds. U.K. 1,081,304 produced similar polymers in the presence of alkylphosphine complexes of palladium as catalyst. Nozaki extended the reaction to produce linear alternating polymers in the presence of arylphosphine complexes of palladium moieties and certain inert solvents. See, for example, U.S. Pat. No. 3,694,412.
More recently the class of linear alternating polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon has become of greater interest in part because of the greater availability of the polymers. More recent processes for the production of such polymers, now becoming known as polyketones or polyketone polymers, are illustrated by a number of published European Patent Applications including 121,965, 181,014, 213,671 and 257,663. The process, now becoming broadly conventional, generally involves the use of a catalyst composition formed from a compound of a Group VIII metal selected from palladium, cobalt or nickel, the anion of a non-hydrohalogenic acid having a pKa below about 6, preferably below 2, and a bidentate ligand of phosphorus, arsenic or antimony.
The resulting polymers are relatively high molecular weight thermoplastics processable by methods conventional for thermoplastics into a variety of shaped articles of established utility. One such utility is in the production of sheets and films useful in the packaging industry which are produced by methods such as extrusion. While such sheets and films have desirable properties, it would be of advantage to provide films of the polyketone polymers having better properties of stiffness and strength.